CVE-2026-73056 json
SiYuan kernel before 3.7.4 Unthrottled Brute-Force via API Token
published 2026-08-16 2 mo ago modified 2026-08-26 2 mo ago also EUVD-2026-59942
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 56%
- public exploits
- 0
- none known
Summary
SiYuan kernel versions before 3.7.4 contain an improper restriction of excessive authentication attempts vulnerability in the CheckAuth() middleware. The middleware accepts the API token (Conf.Api.Token) via an Authorization header (Token/Bearer) or a ?token= query parameter, and neither path is protected by the application's CAPTCHA/lockout mechanism (NeedCaptcha/WrongAuthCount). As a result, an unauthenticated remote attacker can perform unlimited automated guesses of the API token, particularly when a short or weak custom token has been configured, and upon success gains full RoleAdministrator access enabling arbitrary file operations and SQL queries.
Patch / fix
- siyuan-note siyuan 3.7.4
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- total
- Assessed
- 2 mo ago
Exploit prediction
0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-m6w6-p7pc-fpg2 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- siyuan-note siyuan
Classification
- Weakness
-
- CWE-307 Improper Restriction of Excessive Authentication Attempts
References
-
github.com
/siyuan-note/siyuan/security/advisories/GHSA-m6w6-p7pc-fpg2
vendor-advisory, exploit
-
vulncheck.com
/advisories/siyuan-kernel-before-unthrottled-brute-force-via-api-token
third-party-advisory
Sources
- CVE List CVE-2026-73056
- NVD CVE-2026-73056
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